Remove a bunch of TOOLKIT_GTK in content/ and gpu/, as well as NPAPI plugins on linux

gpu/gles2_conform_support/native/main.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "base/at_exit.h"
 #include "base/command_line.h"
 #include "base/message_loop/message_loop.h"
 #if defined(OS_MACOSX)
 #include "base/mac/scoped_nsautorelease_pool.h"
 #endif
 #include "ui/gl/gl_surface.h"
 
-#if defined(TOOLKIT_GTK)
-#include "ui/gfx/gtk_util.h"
-#endif
-
 extern "C" {
 #if defined(GLES2_CONFORM_SUPPORT_ONLY)
 #include "gpu/gles2_conform_support/gtf/gtf_stubs.h"
 #else
 #include "third_party/gles2_conform/GTF_ES/glsl/GTF/Source/GTFMain.h"
 #endif
 }
 
 int main(int argc, char *argv[]) {
   base::AtExitManager at_exit;
   CommandLine::Init(argc, argv);
   base::MessageLoopForUI message_loop;
 
 #if defined(OS_MACOSX)
   base::mac::ScopedNSAutoreleasePool pool;
 #endif
-#if defined(TOOLKIT_GTK)
-  gfx::GtkInitFromCommandLine(*CommandLine::ForCurrentProcess());
-#endif
-
   GTFMain(argc, argv);
 
   return 0;
 }